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Sphingoid base is required for translation initiation during heat stress in Saccharomyces cerevisiae |
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Published in | Molecular biology of the cell. 2006, vol. 17, p. 1164-1175 | |
Abstract | Sphingolipids are required for many cellular functions including response to heat shock. We analyzed the yeast lcb1-100 mutant, which is conditionally impaired in the first step of sphingolipid biosynthesis and shows a strong decrease in heat shock protein synthesis and viability. Transcription and nuclear export of heat shock protein mRNAs is not affected. However, lcb1-100 cells exhibited a strong decrease in protein synthesis caused by a defect in translation initiation under heat stress conditions. The essential lipid is sphingoid base, not ceramide or sphingoid base phosphates. Deletion of the eIF4E-binding protein Eap1p in lcb-100 cells restored translation of heat shock proteins and increased viability. The translation defect during heat stress in lcb1-100 was due at least partially to a reduced function of the sphingoid base-activated PKH1/2 protein kinases. In addition, depletion of the translation initiation factor eIF4G was observed in lcb1-100 cells and ubiquitin overexpression allowed partial recovery of translation after heat stress. Taken together, we have shown a requirement for sphingoid bases during the recovery from heat shock and suggest that this reflects a direct lipid-dependent signal to the cap-dependent translation initiation apparatus. | |
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Citation (ISO format) | MEIER, Karsten D. et al. Sphingoid base is required for translation initiation during heat stress in Saccharomyces cerevisiae. In: Molecular biology of the cell, 2006, vol. 17, p. 1164-1175. https://archive-ouverte.unige.ch/unige:82045 |